Unity3D v2.0.0-rc2

• Added UnityVersionMajor, UnityVersionMinor, UnityVersionPatch, and UnityVersionAsNumber props for manipulation of Unity versions as numbers
• Updated usage notes in all Readme documents
• Added test projects for Tech Stream Unity releases up through 2022.1
• BREAKING CHANGES:
  • Renamed OSInstallRoot property to OSInstallRootPath and UnityInstallRoot to UnityInstallRootPath, to be consistent with other prop names
  • Assembly short-hand properties are now conditionally defined based on UnityVersion